This UCLA Symposium will address the biology of sarcomas. Inquiry in cell biology, molecular biology, and cytogenetics is focusing increasingly on clinical material as well as laboratory cell lines. Many new insights into the biology of sarcomas have resulted and include: Identification of specific chromosomal translocation or molecular genetic changes in some rhabdomyosarcomas, Ewing sarcomas and synovial sarcomas; the potential involvement of chromosome 13 in retinoblastoma (rb-1) locus in osteosarcoma; and altered patterns of growth factor synthesis and response in sarcoma cells. This meeting will view recent developments in sarcoma biology from a wide variety of disciplines. There is considerable new information with great potential for initiating further advances in the diagnosis and treatment of sarcomas. Moreover, vast amounts of clinical material have not been exploited in laboratory investigations. This meeting will, therefore, employ strategies for enhancing communications between basis and clinical scientists who wish to explore areas of mutual interest and possible collaboration.